The application of an abrasive dentifrice paste is generally known to clean and polish teeth. Similarly, other dentifrice compounds are applied to the surfaces of teeth in numerous other dental procedures to bleach, abrade, or otherwise treat a variety of dental conditions. Most commonly, such procedures are performed by a dentist, dental hygienist, or dental assistant using a motorized handpiece which receives what is commonly referred to in the art as a “prophylaxis angle” or “prophy angle.” Typically, the prophylaxis angle is mounted at a right angle to the handpiece, and has a rotating polishing surface that is rotated by the motorized action of the handpiece, and receives dentifrice as it rotates from a cup mounted on the prophylaxis angle. The dentifrice contained within the cup on the prophylaxis angle is replaced as needed by the operator, typically by dipping the prophylaxis angle into a container of dentifrice and scooping out additional dentifrice as desired.
As conventionally deployed, the dentifrice used in prophylaxis angles has been generally in a paste, cream, or other gummy amalgam form. Powdered dentifrices have also been commonly used, generally with sufficient moisture added to create a paste-like preparation for application.
Formerly, most prophylaxis angles were supplied and used as multi-use devices, requiring cleaning and/or sterilization between use for different patients. With the advent of cost-efficient, disposable manufacturing materials and techniques, and with the growing concern over the prevention of transmittable diseases during dental therapy, the use of single-use, disposable prophylaxis angles has become commonplace.
Although the development of disposable prophylaxis angles has had significant impact on dental practice, problems still exist relating to the application of dentifrice to a patient's teeth using an existing disposable prophylaxis angle. Conventional disposable prophylaxis angles may effectively prevent the spread of disease from patient to patient, but do not completely protect the dentist or other operator from potential exposure during use. The container of dentifrice is often held on the finger of the operator. Digital pressure must then be employed with the dentifrice to apply it to the cup of the prophylaxis angle, and such pressure may often stall the drive motor that drives the prophylaxis angle. As the digital pressure is released, the drive motor overcomes the stalling pressure, and the rotational speed of the prophylaxis cup may suddenly increase, potentially spraying buccal debris such as saliva, blood, and tissue particles into the surrounding work environment. This phenomenon is commonly referred to as “splatter,” and may occur even in the presence of a minimal amount of buccal debris. Exposure to such debris can pose a significant health risk to the dentist and/or other operators who are attending the patient.
Past attempts have been made to incorporate dispensable dentifrice within the prophylaxis angle device. However, these efforts have generally failed because of technical disadvantages that prevented their acceptance in the dental marketplace. Among other problems, early prophylaxis angles incorporating paste were not disposable. Additionally, other paste delivery mechanisms were relatively mechanically complex and therefore cost prohibitive.
Furthermore, previously attempted mechanisms for delivering paste contained within a prophylaxis angle are not ergonomically sound and impinge on an operator's ability to control the handpiece. For example, mechanisms on the prophylaxis angle that require pushing a plunger, lever, or knob forward in a direction away from the handpiece may cause loosening of the prophylaxis angle from the handpiece or otherwise interfere with the typical slidable attachment of the prophylaxis angle to the handpiece. Also, mechanisms that require the operator to push a plunger, lever, or knob down in a direction perpendicular to the axis of the prophylaxis angle may interfere with the operator's control and direction of the prophylaxis angle when operating the device, forcing the operator to manipulate the prophylaxis angle counter to the preferred movement during treatment.
For example, disposable prophylaxis angles having internal paste delivery systems using an auger-like structure of the type proposed in the related art must overcome problems associated with charging an internal reservoir with dentifrice material either before or after the auger is assembled into the prophylaxis angle. Either way, the helical blades of the auger, which typically extend for a substantial portion of the internal diameter of the fluid reservoir, make it difficult to fully charge the reservoir with the dentifrice material. Also, the auger blades make advancement of the dentifrice material dependent on the direction of rotation and rotational speed of the auger.
Prophylaxis angles as previously known in the related art are also too large to be practical or were generally more difficult to use and required retraining the practitioner before use on a patient.
Recent efforts to improve a prophylaxis angle are disclosed in U.S. Pat. No. 6,257,886 to Warner, U.S. Pat. No. 6,382,971 to Randolph, U.S. Pat. No. 5,692,901 to Roth et al., and U.S. Pat. No. 5,871,353 to Pierce et al. These cited prophylaxis angles, while they may represent improvements upon certain aspects of the preceding art, continue to be designed around a central rotational axis, which requires more complex engineering to allow for a pathway for dentifrice flow and mechanisms for advancement of the dentifrice. Furthermore, prior methods for manufacturing prophylaxis angles are having more complexly engineered solutions are similarly complex, lacking a simplified, efficient method for alignment and assembly of the constituent components.
The prophylaxis angle disclosed in U.S. Pat. No. 7,070,412 entitled “Self-contained Dental Prophylaxis Angle With Offset Rotation Axis” issued on Jul. 4, 2006 (incorporated by reference in its entirety) provides a dramatic improvement for the delivery of dentifrice material through the angle body with an offset rotational axis, however the mechanism for advancement are not ideally suited.
Accordingly, certain deficiencies also persist among existing prophylaxis angles, leaving a need for further improvement in the design, use, applications, and methods for manufacturing such devices. More specifically, there exists a need for improved mechanisms for advancing therapeutic agents contained within improved prophylaxis angles. There exists a further need for improved design and methods of manufacturing self-contained prophylaxis angles.